textproduct: Albany

WHAT HAS CHANGED

Snowfall amounts for Sunday, mainly in the southwest Adirondacks, southern Greens, western MA and Litchfield County, CT, have increased. There is low to medium confidence in needing winter weather advisories for slippery travel conditions but since this event is occurring over the weekend and over a rather long window, have not issued any advisories in collaboration with WFO Boston and Burlington.

The coastal low for Sunday has trended further east with little if any impacts for eastern NY and western New England. Therefore, this hazard was removed from the key messages. We will continue to monitor trends.

KEY MESSAGES

1) Dress warmly and in layers this morning as wind chill values or "feels-like" temperatures will range from -5F to +5F across much of eastern NY and western New England (even as low -10F to -20F in the higher terrain) for your Friday morning commute.

2) Slippery travel possible on Saturday as a weak disturbance results in periods of snow showers and light snow accumulations. There is moderate confidence in needing winter weather advisories in western New England (especially southern Vermont) where there is a 40 to 70% chance in exceeding 3 inches of snow.

3) High confidence in below normal temperatures for much of next week with increasing confidence for moderate lake effect snow accumulations for the western Adirondacks Monday through Wednesday.

DISCUSSION

KEY MESSAGE 1...

Brisk west to northwest winds 10-15 mph with some gusts 20-30 mph will continue this morning. Since it will be cold this morning as we start the day in the single digits and teens, the combination of brisk winds and chilly temperatures will result in wind chills/"feels-like" temperatures between +5F and -5F with -10F to -20F in the southwest Adirondacks and southern Greens. Bundle up for your Friday morning commute!

KEY MESSAGE 2...

A positively tilted trough becomes established upstream over the Midwest tonight into Saturday and with large scale ridging over the Atlantic, rather strong southwest flow develops over the Northeast. Weak shortwaves embedded within the southwest flow tracking along a southwest to northeast oriented mid-level thermal and moisture gradient will aid in periods of snow showers developing across eastern NY and western New England. During periods of stronger warm air advection and enhanced cyclonic vorticity advection, snow showers will likely become steadier and more widespread as forecast soundings show forcing for ascent intersecting the DGZ at times, especially during periods where FGEN in the 850-700hPa layer increases. Southwest flow upsloping the terrain in the southwest Adirondacks, southern VT, the Taconics, western MA, and Litchfield County looks to result in instances of moderate snow.

There remains discrepancies on how much QPF occurs within these periods of snow with the spread for the 24hr QPF between the NBM 25th and 75th percentile still nearly 0.25" across much of the region from 06 UTC Sat to 06 UTC Sun. However, within typical southwest flow regimes, the Capital District tends to be a QPF minimum due to downsloping off the Catskills while the south facing slopes of the southern Adirondacks as well as the west facing slopes of the Taconics and along the terrain in western New England tend to be higher due to upslope enhancements. Therefore, there is low to moderate confidence that these favored areas will need a winter weather advisory as our latest snowfall forecast has increased to 2 to 5 inches with even locally higher amounts 4 to 6 inches in the southern Greens of southern VT. There is also a 40 to 70% chance for snowfall amounts to exceed 3 inches per the latest NBM in these areas. Given this event is occurring on a weekend and over a rather long window between 06 UTC Saturday and 00 UTC Sunday, we held off on advisories but will monitor trends. Elsewhere, snowfall totals are lower ranging from 0.5 - 2 inches and with temperatures trending above freezing into the low to mid 30s during the day Saturday, heavily traveled roads should see lower accumulations. Either way, if you plan to be out and about on Saturday, be mindful of potential slippery conditions from periods of snow showers through the day resulting in light snow accumulations.

KEY MESSAGE 3...

Confidence remains rather high that our overall pattern turns cold for much of next week. Arctic air surges into the Northeast in the wake of a clipper on Monday with the cold air mass entrenched over the region through the middle of the week thanks to persistent westerly flow. Both the NAEFS and the ECMWF ENS show the incoming air mass ranking below the 10th percentile of the CFSR climatology period within mid to late January. The NBM continues to suggest that the probability for overnight low temperatures to fall under 10 F will be over 50% percent for much of the area Tuesday night and Wednesday night. Tuesday looks to be the coldest day with the NBM showing greater than 60% chance for daytime temperatures to fall below 20F! The cold combined with breezy winds Monday night into Tuesday also raises concerns for potential hazardous wind chill values as most will likely be below zero. Highest confidence for potential cold weather advisories looks to be in the southwest Adirondacks, parts of Berkshire County, the eastern Catskills, and the southern Greens where there may be an increased risk for hypothermia and frostbite.

Westerly winds tracking the Arctic air mass over the Great Lakes also sets the stage for a multi-lake connection to support impressive lake effect bands that extend eastward off Lake Ontario, including into the western Adirondacks. There is moderate confidence in moderate snow accumulations here but amounts may be higher depending on the residence time and intensity of the lake effect bands. Depending on how winds veer, bands may also shift southward into the western Mohawk Valley and southern Greens at times, leading to at least light snow accumulation.

AVIATION /07Z FRIDAY THROUGH TUESDAY/

Through 06z/Sat...An upper level trough overhead will depart the region by Friday morning. This may bring some brief snow showers to KALB/KPSF between 06-10z/Fri with IFR/MVFR vsbys. Otherwise, cigs will be mostly VFR at KALB/KGFL/KPOU and MVFR at KPSF lifting to VFR Friday morning. VFR conditions are then expected for the remainder of the TAF period. Another disturbance will approach the TAF sites Friday night and may bring some light snow to some sites just prior to 06z/Sat. Will address this potential in the next TAF update.

Wind will be westerly overnight through Friday at 10-20 kt with gusts 20-30 kt before diminishing and becoming southerly Friday evening.

Outlook...

Saturday Night: Low Operational Impact. NO SIG WX. Sunday: Low Operational Impact. Slight Chance of SN. Sunday Night: No Operational Impact. NO SIG WX. Martin Luther King Jr Day: Low Operational Impact. Chance of SHSN. Monday Night: Low Operational Impact. Breezy. NO SIG WX. Tuesday: Low Operational Impact. Breezy. NO SIG WX. Tuesday Night: No Operational Impact. NO SIG WX. Wednesday: Low Operational Impact. Slight Chance of SHSN.

ALY WATCHES/WARNINGS/ADVISORIES

CT...None. NY...None. MA...None. VT...None.